Events like this are what it means to The Queen. This is what it's all about. Power. Having all those heads of state bowing down to you. She'll be absolutely loving it. And then there's a wedding of course. Just a side issue that for The Queen.
The Queen is a Constitutional Head of State, not a ruling Monarch. Heads of State bowing to her is a matter of tradition and courtesy. It would be a sad state of affairs if the masses of people who turned out in support of the wedding didn't have such occasions when they can celebrate and share the enjoyment.
R1: Although I agree with your sentiments, must you call anyone who disagrees with you unpleasant names? It is an emotive subject for many, but your point to those with whom you disagree would be better made if you refrained from personal attacks. Just a suggestion.